This invention relates to tools and methods for removing the raised edge or burr which is left when a hole is drilled, punched, or similarly formed through a plate, pipe, duct, or similar workpiece. The tool and method of this invention are particularly intended for removing the burr on the edge of a hole away from the operator of the tool, e.g., the burr on the edge of a hole on the side of a plate away from the operator or on the inside of a pipe or duct.
Tools for deburring the remote edges of holes through plates, pipes, ducts, and the like are known. Typically, these tools include a longitudinal shaft having a pivotal deburring blade at or near the remote or distal end of the shaft. The shaft is inserted through the hole while the deburring blade is pivoted substantially parallel to the shaft in an inoperative position. When the blade is through the hole, the blade is pivoted out substantially perpendicular to the shaft into an operative position. The shaft is then rotated and the tool is pulled outwardly of the hole so that the blade engages and eventually removes the burr. When the burr has been removed to the desired degree, the blade is pivoted back into the inoperative position in the shaft so that the tool can be removed from the hole.
In general, the pivoting of the blade in the prior art deburring tools described above is positively controlled by means accessible to the operator from the near side of the hole. Control of the blade from the near side of the hole is desirable for operator convenience, and in many instances is absolutely essential if the operator cannot reach the inside of the hole, as in the case of a hole through a long pipe or duct. Typically, the means for controlling the pivoting of the blade in these prior art tools includes additional elements associated with the shaft, at least one of which extends through the hole substantially parallel to the shaft. The operator manipulates this apparatus (e.g., by reciprocating it) to position the blade.
This additional apparatus in prior art deburring tools greatly complicates these tools and may substantially increase their cost. The relatively large number of moving parts in these tools renders them more susceptible to damage and wear and reduces their reliability. The burr material removed by these tools can become lodged in the moving parts of the tools and cause them to jam.
In view of the foregoing, it is an object of this invention to improve and simplify tools and methods for deburring the edges of holes remote from the operator of the tool.
It is a more particular object of this invention to provide a deburring tool for use in removing the burrs on the remote edges of holes in which the blade can be controlled solely by simple manipulation of the tool relative to the hole and without the need for any additional elements for positioning the blade.